Gamma-Irradiation Dependency of EPR and TL-Spectra of Quartz

Plötze, Michael; Wolf, D.; Krbetschek, Matthias

doi:10.1007/978-3-642-22161-3_8

Cited by 3 publications

(1 citation statement)

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“…The attribution of γ-induced BTL to the [AlO4] 0 centre was also proposed by Plötze et al (2012) based on EPR measurements and TL spectrometry, which demonstrated an EPR saturation dose of this centre of ~1 MGy. The fact that no increase in the BTL >250 °C could be induced by additive β-irradiation of sample BT1629 (estimated natural dose of a few hundred kGy) while younger samples still yielded growing BTL signals in that temperature region supports the assignment of the [AlO4] 0 centre to this emission and indicates that this centre is stable over geological periods.…”

Section: Emission Spectra and Associated Defectsmentioning

confidence: 76%

Quartz thermoluminescence spectra in the high-dose range

Schmidt

Woda

2019

Phys Chem Minerals

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The red thermoluminescence (RTL) emission of quartz is associated with advantageous features such as high saturation dose and good reproducibility. Previous studies, however, noted inexplicable RTL glow curve shapes with new peaks at large doses (kGy range). Here we present TL spectra of two granitic quartz samples over the additive γ-dose range 0.1-47.9 kGy. While for doses between 0.4 and 1 kGy the TL spectra are dominated by the red emission at 1.95 eV (630 nm), a blue emission at 2.67 eV (465 nm) becomes prominent for higher doses. For one sample, this blue component completely dominates the spectrum for doses >12.2 kGy with intensity maxima around 200 °C and >350 °C (heating rate 2 K s-1). The other sample still contains well resolvable red and blue emissions at the largest dose with similar TL peak positions. Signal saturation for the blue emission in the glow curve range 260-300 °C is not yet reached following an additive γ-dose of 47.9 kGy, whereas the red emission generally shows a more subdued signal response for doses >5-12 kGy. These findings agree qualitatively with additional monochromatic blue and red TL measurements on the same samples. The evolution of supplementary radiofluorescence spectra over the entire γ-dose range is more complex, but suggests that the sensitisation of the blue wavelength region occurs during heating and not during irradiation and through creation of electron traps rather than recombination centres (most likely [AlO4] 0 sites). The sharp sensitivity increase at 1 kGy might likewise be related to alkali ion redistribution and/or the removal of non-radiative competitive recombination pathways. While the blue emission still requires thorough investigation, care should be taken when recording RTL using optical filters since significant portions of the registered TL could originate from the blue component entering the RTL transmission window. In practical terms, the dose-dependent change in relative intensities of blue and red TL emissions might help in detecting exposure to high doses.

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Section: Emission Spectra and Associated Defectsmentioning

confidence: 76%